From cdc78b1d6bd7b48ec05d78fc6e6cd98473f40357 Mon Sep 17 00:00:00 2001 From: Tomasz Bursztyka Date: Mon, 19 Aug 2013 15:04:02 +0300 Subject: nft: convert rule into a command state structure This helps to reduce the code complexity to have one single common path for printing, saving and looking up for the rule. Signed-off-by: Tomasz Bursztyka Signed-off-by: Pablo Neira Ayuso --- iptables/nft.c | 477 +++++++++------------------------------------------------ 1 file changed, 73 insertions(+), 404 deletions(-) (limited to 'iptables/nft.c') diff --git a/iptables/nft.c b/iptables/nft.c index 28e71d8f..3b393cc7 100644 --- a/iptables/nft.c +++ b/iptables/nft.c @@ -782,224 +782,16 @@ err: return ret == 0 ? 1 : 0; } -static void nft_match_save(struct nft_rule_expr *expr) -{ - const char *name; - const struct xtables_match *match; - struct xt_entry_match *emu; - const void *mtinfo; - size_t len; - - name = nft_rule_expr_get_str(expr, NFT_EXPR_MT_NAME); - - match = xtables_find_match(name, XTF_TRY_LOAD, NULL); - if (match == NULL) - return; - - mtinfo = nft_rule_expr_get(expr, NFT_EXPR_MT_INFO, &len); - if (mtinfo == NULL) - return; - - emu = calloc(1, sizeof(struct xt_entry_match) + len); - if (emu == NULL) - return; - - memcpy(&emu->data, mtinfo, len); - - if (match->alias) - printf("-m %s", match->alias(emu)); - else - printf("-m %s", match->name); - - /* FIXME missing parameter */ - if (match->save) - match->save(NULL, emu); - - printf(" "); - - free(emu); -} - -static void nft_target_save(struct nft_rule_expr *expr) -{ - const char *name; - const struct xtables_target *target; - struct xt_entry_target *emu; - const void *tginfo; - size_t len; - - name = nft_rule_expr_get_str(expr, NFT_EXPR_TG_NAME); - - /* Standard target not supported, we use native immediate expression */ - if (strcmp(name, "") == 0) { - printf("ERROR: standard target seen, should not happen\n"); - return; - } - - target = xtables_find_target(name, XTF_TRY_LOAD); - if (target == NULL) - return; - - tginfo = nft_rule_expr_get(expr, NFT_EXPR_TG_INFO, &len); - if (tginfo == NULL) - return; - - emu = calloc(1, sizeof(struct xt_entry_match) + len); - if (emu == NULL) - return; - - memcpy(emu->data, tginfo, len); - - if (target->alias) - printf("-j %s", target->alias(emu)); - else - printf("-j %s", target->name); - - /* FIXME missing parameter */ - if (target->save) - target->save(NULL, emu); - - free(emu); -} - -static void nft_immediate_save(struct nft_rule_expr *expr) -{ - uint32_t verdict; - - verdict = nft_rule_expr_get_u32(expr, NFT_EXPR_IMM_VERDICT); - - switch(verdict) { - case NF_ACCEPT: - printf("-j ACCEPT"); - break; - case NF_DROP: - printf("-j DROP"); - break; - case NFT_RETURN: - printf("-j RETURN"); - break; - case NFT_GOTO: - printf("-g %s", - nft_rule_expr_get_str(expr, NFT_EXPR_IMM_CHAIN)); - break; - case NFT_JUMP: - printf("-j %s", - nft_rule_expr_get_str(expr, NFT_EXPR_IMM_CHAIN)); - break; - } -} - -static void -nft_print_meta(struct nft_rule_expr *e, struct nft_rule_expr_iter *iter) -{ - uint8_t key = nft_rule_expr_get_u8(e, NFT_EXPR_META_KEY); - uint32_t value; - const char *name; - char ifname[IFNAMSIZ]; - const char *ifname_ptr; - size_t len; - - e = nft_rule_expr_iter_next(iter); - if (e == NULL) - return; - - name = nft_rule_expr_get_str(e, NFT_RULE_EXPR_ATTR_NAME); - /* meta should be followed by cmp */ - if (strcmp(name, "cmp") != 0) { - DEBUGP("skipping no cmp after meta\n"); - return; - } - - switch(key) { - case NFT_META_IIF: - value = nft_rule_expr_get_u32(e, NFT_EXPR_CMP_DATA); - if_indextoname(value, ifname); - - switch(nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP)) { - case NFT_CMP_EQ: - printf("-i %s ", ifname); - break; - case NFT_CMP_NEQ: - printf("! -i %s ", ifname); - break; - } - break; - case NFT_META_OIF: - value = nft_rule_expr_get_u32(e, NFT_EXPR_CMP_DATA); - if_indextoname(value, ifname); - - switch(nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP)) { - case NFT_CMP_EQ: - printf("-o %s ", ifname); - break; - case NFT_CMP_NEQ: - printf("! -o %s ", ifname); - break; - } - break; - case NFT_META_IIFNAME: - ifname_ptr = nft_rule_expr_get(e, NFT_EXPR_CMP_DATA, &len); - memcpy(ifname, ifname_ptr, len); - ifname[len] = '\0'; - - /* if this is zero, then assume this is a interface mask */ - if (if_nametoindex(ifname) == 0) { - ifname[len] = '+'; - ifname[len+1] = '\0'; - } - - switch(nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP)) { - case NFT_CMP_EQ: - printf("-i %s ", ifname); - break; - case NFT_CMP_NEQ: - printf("! -i %s ", ifname); - break; - } - break; - case NFT_META_OIFNAME: - ifname_ptr = nft_rule_expr_get(e, NFT_EXPR_CMP_DATA, &len); - memcpy(ifname, ifname_ptr, len); - ifname[len] = '\0'; - - /* if this is zero, then assume this is a interface mask */ - if (if_nametoindex(ifname) == 0) { - ifname[len] = '+'; - ifname[len+1] = '\0'; - } - - switch(nft_rule_expr_get_u8(e, NFT_EXPR_CMP_OP)) { - case NFT_CMP_EQ: - printf("-o %s ", ifname); - break; - case NFT_CMP_NEQ: - printf("! -o %s ", ifname); - break; - } - break; - default: - DEBUGP("unknown meta key %d\n", key); - break; - } -} - -static void -nft_print_counters(struct nft_rule_expr *e, struct nft_rule_expr_iter *iter, - bool counters) -{ - if (counters) { - printf("-c %"PRIu64" %"PRIu64" ", - nft_rule_expr_get_u64(e, NFT_EXPR_CTR_PACKETS), - nft_rule_expr_get_u64(e, NFT_EXPR_CTR_BYTES)); - } -} - void -nft_rule_print_save(struct nft_rule *r, enum nft_rule_print type, bool counters) +nft_rule_print_save(const struct iptables_command_state *cs, + struct nft_rule *r, enum nft_rule_print type, + unsigned int format) { - struct nft_rule_expr_iter *iter; - struct nft_rule_expr *expr; const char *chain = nft_rule_attr_get_str(r, NFT_RULE_ATTR_CHAIN); + int family = nft_rule_attr_get_u8(r, NFT_RULE_ATTR_FAMILY); + struct xtables_rule_match *matchp; + struct nft_family_ops *ops; + int ip_flags = 0; /* print chain name */ switch(type) { @@ -1011,34 +803,33 @@ nft_rule_print_save(struct nft_rule *r, enum nft_rule_print type, bool counters) break; } - iter = nft_rule_expr_iter_create(r); - if (iter == NULL) - return; - - expr = nft_rule_expr_iter_next(iter); - while (expr != NULL) { - const char *name = - nft_rule_expr_get_str(expr, NFT_RULE_EXPR_ATTR_NAME); + ops = nft_family_ops_lookup(family); + ip_flags = ops->save_firewall(cs, format); - if (strcmp(name, "counter") == 0) { - nft_print_counters(expr, iter, counters); - } else if (strcmp(name, "payload") == 0) { - struct nft_family_ops *ops = nft_family_ops_lookup( - nft_rule_attr_get_u8(r, NFT_RULE_ATTR_FAMILY)); - ops->print_payload(expr, iter); - } else if (strcmp(name, "meta") == 0) { - nft_print_meta(expr, iter); - } else if (strcmp(name, "match") == 0) { - nft_match_save(expr); - } else if (strcmp(name, "target") == 0) { - nft_target_save(expr); - } else if (strcmp(name, "immediate") == 0) { - nft_immediate_save(expr); - } + for (matchp = cs->matches; matchp; matchp = matchp->next) { + if (matchp->match->alias) { + printf("-m %s", + matchp->match->alias(matchp->match->m)); + } else + printf("-m %s", matchp->match->name); - expr = nft_rule_expr_iter_next(iter); + if (matchp->match->save != NULL) + matchp->match->save(NULL, matchp->match->m); + printf(" "); } + if (cs->target != NULL) { + if (cs->target->alias) { + printf("-j %s", cs->target->alias(cs->target->t)); + } else + printf("-j %s", cs->jumpto); + + if (cs->target->save != NULL) + cs->target->save(NULL, cs->target->t); + } else if (strlen(cs->jumpto) > 0) + printf("-%c %s", ip_flags & IPT_F_GOTO ? 'g' : 'j', + cs->jumpto); + printf("\n"); } @@ -1219,11 +1010,15 @@ int nft_rule_save(struct nft_handle *h, const char *table, bool counters) while (r != NULL) { const char *rule_table = nft_rule_attr_get_str(r, NFT_RULE_ATTR_TABLE); + struct iptables_command_state cs = {}; if (strcmp(table, rule_table) != 0) goto next; - nft_rule_print_save(r, NFT_RULE_APPEND, counters); + nft_rule_to_iptables_command_state(r, &cs); + + nft_rule_print_save(&cs, r, NFT_RULE_APPEND, + counters ? 0 : FMT_NOCOUNTS); next: r = nft_rule_list_iter_next(iter); @@ -1661,187 +1456,58 @@ next: return 0; } -static int matches_howmany(struct xtables_rule_match *matches) -{ - struct xtables_rule_match *matchp; - int matches_ctr = 0; - - for (matchp = matches; matchp; matchp = matchp->next) - matches_ctr++; - - return matches_ctr; -} - static bool -__find_match(struct nft_rule_expr *expr, struct xtables_rule_match *matches) +compare_matches(struct xtables_rule_match *mt1, struct xtables_rule_match *mt2) { - const char *matchname = nft_rule_expr_get_str(expr, NFT_EXPR_MT_NAME); - /* Netlink aligns this match info, don't trust this length variable */ - const char *data = nft_rule_expr_get_str(expr, NFT_EXPR_MT_INFO); - struct xtables_rule_match *matchp; - bool found = false; + struct xtables_rule_match *mp1; + struct xtables_rule_match *mp2; - for (matchp = matches; matchp; matchp = matchp->next) { - struct xt_entry_match *m = matchp->match->m; + for (mp1 = mt1, mp2 = mt2; mp1 && mp2; mp1 = mp1->next, mp2 = mp2->next) { + struct xt_entry_match *m1 = mp1->match->m; + struct xt_entry_match *m2 = mp2->match->m; - if (strcmp(m->u.user.name, matchname) != 0) { + if (strcmp(m1->u.user.name, m2->u.user.name) != 0) { DEBUGP("mismatching match name\n"); - continue; + return false; } - if (memcmp(data, m->data, m->u.user.match_size - sizeof(*m)) != 0) { - DEBUGP("mismatch match data\n"); - continue; + if (m1->u.user.match_size != m2->u.user.match_size) { + DEBUGP("mismatching match size\n"); + return false; } - found = true; - break; - } - - return found; -} -static bool find_matches(struct xtables_rule_match *matches, struct nft_rule *r) -{ - struct nft_rule_expr_iter *iter; - struct nft_rule_expr *expr; - int kernel_matches = 0; - - iter = nft_rule_expr_iter_create(r); - if (iter == NULL) - return false; - - expr = nft_rule_expr_iter_next(iter); - while (expr != NULL) { - const char *name = - nft_rule_expr_get_str(expr, NFT_RULE_EXPR_ATTR_NAME); - - if (strcmp(name, "match") == 0) { - if (!__find_match(expr, matches)) - return false; - - kernel_matches++; + if (memcmp(m1->data, m2->data, + m1->u.user.match_size - sizeof(*m1)) != 0) { + DEBUGP("mismatch match data\n"); + return false; } - expr = nft_rule_expr_iter_next(iter); } - nft_rule_expr_iter_destroy(iter); - /* same number of matches? */ - if (matches_howmany(matches) != kernel_matches) - return false; - - return true; -} - -static bool __find_target(struct nft_rule_expr *expr, struct xt_entry_target *t) -{ - size_t len; - const char *tgname = nft_rule_expr_get_str(expr, NFT_EXPR_TG_NAME); - /* Netlink aligns this target info, don't trust this length variable */ - const char *data = nft_rule_expr_get(expr, NFT_EXPR_TG_INFO, &len); - - if (strcmp(t->u.user.name, tgname) != 0) { - DEBUGP("mismatching target name\n"); + /* Both cursors should be NULL */ + if (mp1 != mp2) { + DEBUGP("mismatch matches amount\n"); return false; } - if (memcmp(data, t->data, t->u.user.target_size - sizeof(*t)) != 0) - return false; - return true; } -static int targets_howmany(struct xtables_target *target) -{ - return target != NULL ? 1 : 0; -} - static bool -find_target(struct xtables_target *target, struct nft_rule *r) +compare_targets(struct xtables_target *tg1, struct xtables_target *tg2) { - struct nft_rule_expr_iter *iter; - struct nft_rule_expr *expr; - int kernel_targets = 0; - - /* Special case: we use native immediate expressions to emulated - * standard targets. Also, we don't want to crash with no targets. - */ - if (target == NULL || strcmp(target->name, "standard") == 0) + if (tg1 == NULL && tg2 == NULL) return true; - iter = nft_rule_expr_iter_create(r); - if (iter == NULL) + if ((tg1 == NULL && tg2 != NULL) || (tg1 != NULL && tg2 == NULL)) return false; - expr = nft_rule_expr_iter_next(iter); - while (expr != NULL) { - const char *name = - nft_rule_expr_get_str(expr, NFT_RULE_EXPR_ATTR_NAME); - - if (strcmp(name, "target") == 0) { - /* we may support several targets in the future */ - if (!__find_target(expr, target->t)) - return false; - - kernel_targets++; - } - expr = nft_rule_expr_iter_next(iter); - } - nft_rule_expr_iter_destroy(iter); - - /* same number of targets? */ - if (targets_howmany(target) != kernel_targets) { - DEBUGP("kernel targets is %d but we passed %d\n", - kernel_targets, targets_howmany(target)); + if (strcmp(tg1->t->u.user.name, tg2->t->u.user.name) != 0) return false; - } - - return true; -} - -static bool -find_immediate(struct nft_rule *r, const char *jumpto) -{ - struct nft_rule_expr_iter *iter; - struct nft_rule_expr *expr; - iter = nft_rule_expr_iter_create(r); - if (iter == NULL) + if (memcmp(tg1->t->data, tg2->t->data, + tg1->t->u.user.target_size - sizeof(*tg1->t)) != 0) { return false; - - expr = nft_rule_expr_iter_next(iter); - while (expr != NULL) { - const char *name = - nft_rule_expr_get_str(expr, NFT_RULE_EXPR_ATTR_NAME); - - if (strcmp(name, "immediate") == 0) { - int verdict = nft_rule_expr_get_u32(expr, NFT_EXPR_IMM_VERDICT); - const char *verdict_name = NULL; - - /* No target specified but immediate shows up, this - * is not the rule we are looking for. - */ - if (strlen(jumpto) == 0) - return false; - - switch(verdict) { - case NF_ACCEPT: - verdict_name = "ACCEPT"; - break; - case NF_DROP: - verdict_name = "DROP"; - break; - case NFT_RETURN: - verdict_name = "RETURN"; - break; - } - - /* Standard target? */ - if (verdict_name && strcmp(jumpto, verdict_name) != 0) - return false; - } - expr = nft_rule_expr_iter_next(iter); } - nft_rule_expr_iter_destroy(iter); return true; } @@ -1911,28 +1577,27 @@ nft_rule_find(struct nft_rule_list *list, const char *chain, const char *table, break; } else { /* Delete by matching rule case */ + nft_rule_to_iptables_command_state(r, &this); + DEBUGP("comparing with... "); #ifdef DEBUG_DEL - nft_rule_print_save(r, NFT_RULE_APPEND, 0); + nft_rule_print_save(&this, r, NFT_RULE_APPEND, 0); #endif - - nft_rule_to_iptables_command_state(r, &this); - if (!ops->is_same(cs, &this)) goto next; - if (!find_matches(cs->matches, r)) { - DEBUGP("matches not found\n"); + if (!compare_matches(cs->matches, this.matches)) { + DEBUGP("Different matches\n"); goto next; } - if (!find_target(cs->target, r)) { - DEBUGP("target not found\n"); + if (!compare_targets(cs->target, this.target)) { + DEBUGP("Different target\n"); goto next; } - if (!find_immediate(r, cs->jumpto)) { - DEBUGP("immediate not found\n"); + if (strcmp(cs->jumpto, this.jumpto) != 0) { + DEBUGP("Different verdict\n"); goto next; } @@ -2324,7 +1989,11 @@ err: static void list_save(struct nft_rule *r, unsigned int num, unsigned int format) { - nft_rule_print_save(r, NFT_RULE_APPEND, !(format & FMT_NOCOUNTS)); + struct iptables_command_state cs = {}; + + nft_rule_to_iptables_command_state(r, &cs); + + nft_rule_print_save(&cs, r, NFT_RULE_APPEND, !(format & FMT_NOCOUNTS)); } static int -- cgit v1.2.3